2001 Volume 17 Issue 10 Pages 1175-1178
It has been demonstrated that a glass-like silicone ladder-type polymer permits one to homogeneously incorporate high amounts of ionophores into the covalently-bonded double chain structure. Furthermore, by making use of this feature, we have successfully fabricated an iodide ion-sensitive field-effect transistor based on two kinds of ionophores and silicone ladder polymer matrix. As ionophores, 5,10,15,20-tetraphenyl-21H,23H-porphyrin and dimethyloctadecyl-3-trimethoxylsilylpropylammonium chloride were homogeneously incorporated into the matrix. The ion-sensitive field-effect transistor showed a linear potential response ranging in the I- concentration between 1.0 × 10-5 and 1.0 × 10-1 M. The selectivity coefficients for I- towards interferences of ClO4- and NO3- were estimated to be KpotI-,ClO4- ≈ 6.2 × 10-4 and KpotI-,NO3- ≈ 4.9 × 10-4. The matrix has proved to be so stable that the selectivity coefficients have not been altered over six months.